海洋沉积物-水界面营养盐交换过程的研究1

对胶州湾和渤海沉积物分别进行室内培养实验.结果表明,在沉积物中加入营养盐后,铵氮、硅酸盐由沉积物向水体的迁移增大,铵氮的迁移在总溶解态氮的交换中起主要作用,其交换量约占总溶解态氮扩散量的76%,硝酸盐及磷酸盐由水体向沉积物的迁移减弱.在上覆水中加入营养盐后,硝酸盐、磷酸盐由水体向沉积物的迁移增大,硝酸氮的迁移占总溶解态氮交换的主要部分,约为62%.铵由沉积物向水体的迁移减弱,硅酸盐变成由水体向沉积物迁移.沉积物对于上覆水中营养盐的浓度具有一定的调节作用.无论在充空气或充氮气条件下,磷及硅的交换速率变化不明显,铵氮的迁移占总溶解态氮扩散量的98%以上.充氧条件下硝酸盐由沉积物向上覆水的迁移通量较充氮气条件增加.比较两种不同的通量计算方法(积分和拟合),结果表明由两种计算方法计算的交换速率的变化趋势基本是一致的.

A STUDY ON THE EXCHANGE OF NUTRIENTS BETWEEN SEDIMENTAND AND SEA WATER

Laboratory incubation experiments were carried out to study the exchange processes of nutrientsbetween sediment and water.The results demonstaled that after adding nutrients to sediment,therelease fluxes of ammonium and silicte increased,while the fluxes of nitrate and phosphate de-creased.The ammonium fluxes were the main composition in total dissolved inorganic nitrogen(TDIN).Adding nutrients to the overlying water,the fluxes of nitrate,phosphate and silicate in-creased,the ammonium fluxes decreased.The fluxes of nitrate were the main part in the TDIN.Sediment can regulate nutrient concentrations in overlying waters.After incubation in air and/or ni-trogen,there was no obvious variation for the exchange fluxes of phosphate and silicate.The am-monium fluxes were the main part in TDIN. The release fluxs of nitrate water increased after incu-bation in air than in nitrogen.The exchange fluxes of nutrients calculated with two different methodsgive similar results.